--- /dev/null
+/*
+ * SH7760 DMABRG IRQ handling
+ *
+ * (c) 2007 MSC Vertriebsges.m.b.H, Manuel Lauss <mlau@msc-ge.com>
+ * licensed under the GPLv2.
+ *
+ */
+
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <asm/dma.h>
+#include <asm/dmabrg.h>
+#include <asm/io.h>
+
+/*
+ * The DMABRG is a special DMA unit within the SH7760. It does transfers
+ * from USB-SRAM/Audio units to main memory (and also the LCDC; but that
+ * part is sensibly placed in the LCDC registers and requires no irqs)
+ * It has 3 IRQ lines which trigger 10 events, and works independently
+ * from the traditional SH DMAC (although it blocks usage of DMAC 0)
+ *
+ * BRGIRQID | component | dir | meaning | source
+ * -----------------------------------------------------
+ * 0 | USB-DMA | ... | xfer done | DMABRGI1
+ * 1 | USB-UAE | ... | USB addr err.| DMABRGI0
+ * 2 | HAC0/SSI0 | play| all done | DMABRGI1
+ * 3 | HAC0/SSI0 | play| half done | DMABRGI2
+ * 4 | HAC0/SSI0 | rec | all done | DMABRGI1
+ * 5 | HAC0/SSI0 | rec | half done | DMABRGI2
+ * 6 | HAC1/SSI1 | play| all done | DMABRGI1
+ * 7 | HAC1/SSI1 | play| half done | DMABRGI2
+ * 8 | HAC1/SSI1 | rec | all done | DMABRGI1
+ * 9 | HAC1/SSI1 | rec | half done | DMABRGI2
+ *
+ * all can be enabled/disabled in the DMABRGCR register,
+ * as well as checked if they occured.
+ *
+ * DMABRGI0 services USB DMA Address errors, but it still must be
+ * enabled/acked in the DMABRGCR register. USB-DMA complete indicator
+ * is grouped together with the audio buffer end indicators, too bad...
+ *
+ * DMABRGCR: Bits 31-24: audio-dma ENABLE flags,
+ * Bits 23-16: audio-dma STATUS flags,
+ * Bits 9-8: USB error/xfer ENABLE,
+ * Bits 1-0: USB error/xfer STATUS.
+ * Ack an IRQ by writing 0 to the STATUS flag.
+ * Mask IRQ by writing 0 to ENABLE flag.
+ *
+ * Usage is almost like with any other IRQ:
+ * dmabrg_request_irq(BRGIRQID, handler, data)
+ * dmabrg_free_irq(BRGIRQID)
+ *
+ * handler prototype: void brgirqhandler(void *data)
+ */
+
+#define DMARSRA 0xfe090000
+#define DMAOR 0xffa00040
+#define DMACHCR0 0xffa0000c
+#define DMABRGCR 0xfe3c0000
+
+#define DMAOR_BRG 0x0000c000
+#define DMAOR_DMEN 0x00000001
+
+#define DMABRGI0 68
+#define DMABRGI1 69
+#define DMABRGI2 70
+
+struct dmabrg_handler {
+ void (*handler)(void *);
+ void *data;
+} *dmabrg_handlers;
+
+static inline void dmabrg_call_handler(int i)
+{
+ dmabrg_handlers[i].handler(dmabrg_handlers[i].data);
+}
+
+/*
+ * main DMABRG irq handler. It acks irqs and then
+ * handles every set and unmasked bit sequentially.
+ * No locking and no validity checks; it should be
+ * as fast as possible (audio!)
+ */
+static irqreturn_t dmabrg_irq(int irq, void *data)
+{
+ unsigned long dcr;
+ unsigned int i;
+
+ dcr = ctrl_inl(DMABRGCR);
+ ctrl_outl(dcr & ~0x00ff0003, DMABRGCR); /* ack all */
+ dcr &= dcr >> 8; /* ignore masked */
+
+ /* USB stuff, get it out of the way first */
+ if (dcr & 1)
+ dmabrg_call_handler(DMABRGIRQ_USBDMA);
+ if (dcr & 2)
+ dmabrg_call_handler(DMABRGIRQ_USBDMAERR);
+
+ /* Audio */
+ dcr >>= 16;
+ while (dcr) {
+ i = __ffs(dcr);
+ dcr &= dcr - 1;
+ dmabrg_call_handler(i + DMABRGIRQ_A0TXF);
+ }
+ return IRQ_HANDLED;
+}
+
+static void dmabrg_disable_irq(unsigned int dmairq)
+{
+ unsigned long dcr;
+ dcr = ctrl_inl(DMABRGCR);
+ dcr &= ~(1 << ((dmairq > 1) ? dmairq + 22 : dmairq + 8));
+ ctrl_outl(dcr, DMABRGCR);
+}
+
+static void dmabrg_enable_irq(unsigned int dmairq)
+{
+ unsigned long dcr;
+ dcr = ctrl_inl(DMABRGCR);
+ dcr |= (1 << ((dmairq > 1) ? dmairq + 22 : dmairq + 8));
+ ctrl_outl(dcr, DMABRGCR);
+}
+
+int dmabrg_request_irq(unsigned int dmairq, void(*handler)(void*),
+ void *data)
+{
+ if ((dmairq > 9) || !handler)
+ return -ENOENT;
+ if (dmabrg_handlers[dmairq].handler)
+ return -EBUSY;
+
+ dmabrg_handlers[dmairq].handler = handler;
+ dmabrg_handlers[dmairq].data = data;
+
+ dmabrg_enable_irq(dmairq);
+ return 0;
+}
+EXPORT_SYMBOL_GPL(dmabrg_request_irq);
+
+void dmabrg_free_irq(unsigned int dmairq)
+{
+ if (likely(dmairq < 10)) {
+ dmabrg_disable_irq(dmairq);
+ dmabrg_handlers[dmairq].handler = NULL;
+ dmabrg_handlers[dmairq].data = NULL;
+ }
+}
+EXPORT_SYMBOL_GPL(dmabrg_free_irq);
+
+static int __init dmabrg_init(void)
+{
+ unsigned long or;
+ int ret;
+
+ dmabrg_handlers = kzalloc(10 * sizeof(struct dmabrg_handler),
+ GFP_KERNEL);
+ if (!dmabrg_handlers)
+ return -ENOMEM;
+
+#ifdef CONFIG_SH_DMA
+ /* request DMAC channel 0 before anyone else can get it */
+ ret = request_dma(0, "DMAC 0 (DMABRG)");
+ if (ret < 0)
+ printk(KERN_INFO "DMABRG: DMAC ch0 not reserved!\n");
+#endif
+
+ ctrl_outl(0, DMABRGCR);
+ ctrl_outl(0, DMACHCR0);
+ ctrl_outl(0x94000000, DMARSRA); /* enable DMABRG in DMAC 0 */
+
+ /* enable DMABRG mode, enable the DMAC */
+ or = ctrl_inl(DMAOR);
+ ctrl_outl(or | DMAOR_BRG | DMAOR_DMEN, DMAOR);
+
+ ret = request_irq(DMABRGI0, dmabrg_irq, IRQF_DISABLED,
+ "DMABRG USB address error", NULL);
+ if (ret)
+ goto out0;
+
+ ret = request_irq(DMABRGI1, dmabrg_irq, IRQF_DISABLED,
+ "DMABRG Transfer End", NULL);
+ if (ret)
+ goto out1;
+
+ ret = request_irq(DMABRGI2, dmabrg_irq, IRQF_DISABLED,
+ "DMABRG Transfer Half", NULL);
+ if (ret == 0)
+ return ret;
+
+ free_irq(DMABRGI1, 0);
+out1: free_irq(DMABRGI0, 0);
+out0: kfree(dmabrg_handlers);
+ return ret;
+}
+subsys_initcall(dmabrg_init);
projects / powerpc.git / commitdiff